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Biomedical subjects

R K Gupta

Publications and source records attributed to R K Gupta.

At least 505 records · Page 28Linked to original sources
PubMed1989

Detection of a tumor-associated glycoprotein antigen in serum and urine of melanoma patients by murine monoclonal antibody (AD1-40F4) in enzyme immunoassay.

The urine of 68% of melanoma patients contains a high molecular weight glycoprotein which is expressed by melanoma cells and reacts with autologous antibody. Since high levels of this antigen in urine correlate with disease recurrence in surgically treated melanoma patients, it has been termed urinary tumor-associated antigen (U-TAA). We report the development of a murine monoclonal IgM antibody (AD1-40F4), which is specific for U-TAA. AD1-40F4 showed the same pattern of reactivity as the allo-antibodies previously used for the detection of U-TAA. The antigen recognized by AD1-40F4 has a high molecular weight (590-620 kilodaltons [kd]) and is heat stable. The AD1-40F4-reactive epitope is a protein. When AD1-40F4 was applied in an enzyme immunoassay, it allowed for the detection of U-TAA in the serum of 64% (33/52) of melanoma patients as opposed to only 5% (1/20) of normal controls. Thus, the murine monoclonal antibody AD1-40F4, which has been specifically developed against an allogeneic antibody defined antigen, U-TAA, appears to be important for immuno-prognosis of human melanoma.

Animals↗
PubMed1989

Active specific immunotherapy in malignant melanoma.

We have recently initiated clinical trials of active specific immunotherapy evaluating a new polyvalent melanoma cell vaccine in patients with high-risk and/or recurrent melanoma. The vaccine has been administered alone, or in combination with low-dose cyclophosphamide, as an immunomodulator of suppressor cells. Cyclophosphamide is effective in lowering suppressor cell activity in some patients undergoing active specific immunotherapy. This is not associated with an enhanced humoral immune response to melanoma-associated antigens, nor is the clinical course of those patients receiving cyclophosphamide favorably influenced. We are hopeful that other immunomodulators, alone or in combination with lower doses of cyclophosphamide, may be effective in some patients, particularly in those patients whose suppressor cell activity remains high. The optimization of the vaccine and the use of immunomodulators will enhance humoral and cellular immune responses to antigens in the allogenic vaccine that cross react with those present in the autologous melanoma, which should more favorably influence the prognosis of melanoma patients.

Antigens, Neoplasm↗
PubMed1989

Induction of antibodies to a tumor-associated antigen by immunization with a whole melanoma cell vaccine.

Urinary-tumor-associated antigen (U-TAA) is a glycoprotein present in the urine of melanoma patients. Previous studies have addressed the role of U-TAA in immunoprognosis. The present investigation was undertaken to determine whether the administration of whole melanoma cell vaccine (MCV) could induce the formation of anti-(U-TAA) antibodies in melanoma patients. The subjects of this study were stage II and III melanoma patients receiving MCV alone or in conjunction with cyclophosphamide. Anti-(U-TAA) IgM and IgG antibody levels were determined by enzyme immunoassay in sequential serum samples from 15 stage II and III melanoma patients receiving MCV. U-TAA purified from the urine of a melanoma patient was used as a target in this assay. The mean anti-(U-TAA) IgM titer prior to vaccination was similar to that of a non-vaccinated melanoma control group (1:1138 +/- 214, n = 15 vs 1:1334 +/- 254, n = 7; P = 0.375) but prevaccination IgG levels were generally higher than in the control group (1:3984 +/- 602 vs 1:2595 +/- 423; 0.1 greater than P greater than 0.05). While only 6 of the 15 patients demonstrated a rise in levels of IgG antibodies (mean 1:2964 +/- 1047 pre-MCV to 1:9958 +/- 2677 post MCV, P less than 0.01), 11 of the 15 patients demonstrated a greater than twofold rise in their anti-(U-TAA) IgM titers following vaccination (1:1051 +/- 259 pre-MCV to 1:2518 +/- 576 post-MCV; P less than 0.005). In addition, patients with visceral metastases consistently elicited anti-(U-TAA) responses equivalent to those with more limited disease. Concomitant administration of cyclophosphamide did not affect the response rates of peak antibody levels. The possibility that these antibody responses were actually against histocompatibility locus antigens (HLA) (contaminating our U-TAA preparation) was ruled out because the target antigen (U-TAA) was devoid of HLA, and because the induction of anti-(U-TAA) antibodies did not correlate with the induction of anti-HLA antibodies. These results demonstrate augmentation of anti-(U-TAA) IgM and IgG antibodies by immunization with the MCV.

Antibodies, Neoplasm↗
PubMed1989

MR evaluation of brachial plexus injuries.

Ten cases of brachial plexus injury were subjected to magnetic resonance (MR) to demonstrate the roots, trunks, divisions or cord abnormalities. Both normal and abnormal brachial plexuses were imaged in sagittal, axial, coronal and axial oblique planes. Myelography, using water soluble contrast agents, was performed in seven cases. MR demonstrated one traumatic meningocele, one extradural cerebrospinal fluid (CSF) collection, trunk and/or root neuromas in four, focal root fibrosis in two and diffuse fibrosis in the remaining two cases. Results of MR were confirmed at surgery in four cases with neuromas, while myelography was normal in two and was not carried out in the remaining two. In two cases, where MR demonstrated diffuse fibrosis of the brachial plexus, myelography showed C7 and T1 traumatic meningocele in one and was normal in the other. Both these patients showed excellent clinical and electrophysiological correlation with MR findings and in one of them surgical confirmation was also obtained. In the other two cases with focal nerve root fibrosis, myelography was normal in one and showed a traumatic meningocele in another. Operative findings in these cases confirmed focal root fibrosis but no root avulsion was observed although seen on one myelogram. Focal fibrosis, however, was noted at operation in more roots than was observed with MR. Initial experience suggests that MR may be the diagnostic procedure of choice for complete evaluation of brachial plexus injuries.

Adolescent↗
PubMed1989

Colonoscopy, mucosal biopsy and brush cytology in the assessment of patients with colorectal inflammatory bowel disease.

Patients with total long-standing mucosal ulcerative colitis are at an increased risk of developing carcinoma of the colon or rectum. Recently it has been suggested that cytological examination of the colon may play an important role in the examination of these patients. The present study was undertaken in order to determine the malignancy/severe dysplasia rate in our patients and to examine the role of cytology in comparison with mucosal biopsy in the detection of mucosal abnormality. Three patients had severe dysplasia in the absence of active inflammation (7.1%). Fifty-four patients were examined concurrently by histology and cytological brushing and at least seven specimens were obtained from each patient. Cytological examination detected active mucosal inflammation more often than histological examination at all sites in the colon. There was good agreement between the cytologists' evaluation, routine histopathological examination and endoscopic evaluation of the colorectal mucosa, although the latter tended to underestimate the degree of active inflammation. It was concluded that, since there was no real improvement in sampling by brush cytology, there may be little advantage in supplementing routine biopsy with brush cytology in patients with long-standing inflammatory bowel disease.

Adult↗
PubMed1989

Primary mediastinal tuberculous abscess: demonstration with MR.

An unusual case of primary mediastinal tuberculous abscess is presented in whom the diagnosis was obtained on magnetic resonance (MR) and ultrasound (US) guided aspiration cytology. Mycobacterium tuberculosis was isolated from direct smear as well as from culture of the "pus". Normal spine signal with MR and normal bone scintigraphy excluded any vertebral focus of infection. MR was helpful in, defining the extent and characterising the abscess, besides excluding a vertebral focus of infection.

Abscess↗
PubMed1989

Studies on the pathology of Marek's disease following challenge in chicks vaccinated with three different vaccines.

The pathology of Marek's disease (MD) was studied in chickens vaccinated separately with three different vaccines, namely herpesvirus of turkeys (HVT), inactivated Marek's disease virus (IMDV) and a bivalent vaccine. The MD-specific mortality following challenge was significantly lower (2.0 per cent) in bivalent vaccinated birds than in those vaccinated with either HVT (5.9 per cent) or IMDV (13.7 per cent) alone. The occurrence, extent and severity of gross lymphomas and lymphoproliferative lesions in visceral organs was lower in the bivalent-vaccinated birds than in other groups. Atrophy and degenerative changes were seen in unvaccinated and challenged birds but not in challenged and bivalent-vaccinated birds. Mild degenerative lesions and slight RE cell hyperplasia occurred in HVT- and IMDV-inoculated and challenged birds. The low intensity and frequency of gross and histological lesions in bivalent-vaccinated birds following challenge is highly suggestive of better vaccine-induced resistance.

Animals↗
PubMed1989

Peritoneal dialysis-associated tuberculous peritonitis in an intravenous drug user with acquired immunodeficiency syndrome.

A rare case of tuberculous peritonitis in a continuous ambulatory peritoneal dialysis (CAPD) patient who has multiple risk factors for extrapulmonary disease due to Mycobacterium tuberculosis is presented. This patient' acute course was atypical with a predominance of neutrophils and low levels of protein in the peritoneal fluid. Obtaining the diagnosis of tuberculous peritonitis by acid-fast smear was also unusual, probably facilitated by centrifugation of large amounts of fluid. The patient was successfully treated without catheter removal. Tuberculosis should be considered in patients with culture-negative CAPD peritonitis.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Lead increases free Ca2+ concentration in cultured osteoblastic bone cells: simultaneous detection of intracellular free Pb2+ by 19F NMR.

Lead (Pb) has been shown to perturb Ca-mediated cellular processes. However, to date, a direct effect of Pb on intracellular free Ca2+ concentration ([Ca2+]i) has not been demonstrated. 19F NMR in combination with 1,2-bis(2-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid (5F-BAPTA) was used to simultaneously measure [Ca2+]i and intracellular free Pb2+ concentration ([Pb2+]i) in the rat osteoblastic bone cell line ROS 17/2.8. The basal concentration of [Ca2+]i in ROS 17/2.8 cells was measured to be 128 +/- 24 nM. Treatment with Pb2+ at 5 and 25 microM produced sustained 50% and 120% increases in [Ca2+]i, respectively, over a time course of 5 hr. At a medium Pb2+ concentration of 25 microM, the entry of Pb2+ into ROS 17/2.8 cells yielded measurable [Pb2+]i in cultured cells. Collectively, these findings advance the hypothesis that Pb toxicity is mediated, in part, through perturbations in [Ca2+]i.

Animals↗
PubMed1989

Laboratory evaluation of face paint repellent formulation using human volunteers under three climatic regimens.

A new combination of repellent with camouflage face paint was evaluated on volunteers against the mosquitoes Aedes aegypti (L.) and Anopheles stephensi (Liston) in an environmental chamber under three climatic regimens: tropical open, tropical forested, and hot dry environments. The duration of protection varied significantly among different climates. The camouflage face paint with diethylmethylbenzamide (deet) provided 95% protection from mosquitoes for 4 h, except under tropical open climate, where it provided only 2 h protection.

Aedes↗
PubMed1989

Technetium-99m radiocolloid scintigraphy, planar and SPECT red blood cell imaging and ultrasonography in diagnosis of hepatic hemangioma.

Technetium-99m planar sulfur colloid scintigraphy, red blood cell imaging and ultrasonography were performed in eighteen patients of hepatic hemangioma to evaluate their diagnostic utility. Radiocolloid scans detected fourteen hemangiomas in 12 patients as focal hepatic defects but missed 9 lesions smaller than 2.5 cm in the other 6 patients, accounting for a 61% sensitivity. All 23 lesions were avascular or normovascular on radionuclide flow study. Serial planar red blood cell scintigraphy showed characteristic gradually increasing focal isotopic accumulation in the 14 hemangiomas which had identifiable cold areas on the radiocolloid study. One of 6 patients with normal radiocolloid scan also showed the typical increasing blood pool pattern of hemangioma, five had normal planar scans till 1 1/2 hours. SPECT red blood cell imaging in these 5 patients detected an additional seven hemangiomas. All 7 lesions were smaller than 2.5 cm. One 1.5 cm hemangioma was missed on both planar and SPECT red blood cell imaging. Region of interest ratios in SPECT transaxial images confirmed gradually increasing concentration of labeled red blood cells in the lesions. Ultrasonography detected 22 of the 23 hemangiomas. Ten were hyperechoic, average size 2.25 cm. Twelve were of mixed pattern, generally larger, average size 7.2 cm. Sonography is useful in the detection of hepatic hemangiomas as a focal mass lesion, but the variable sonographic appearance precludes a definite pathological diagnosis. Technetium-99m red blood cell imaging appears a sensitive technique in detection of hepatic hemangioma, with SPECT being especially useful in locating smaller lesions. The addition of useful in locating smaller lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Magnetic resonance in obstructive jaundice.

Twelve cases of obstructive jaundice in whom ultrasound failed to demonstrate the site and/or the cause of obstruction of the biliary tract were examined with magnetic resonance imaging (MRI), correctly diagnosing the site and cause of obstruction in 10 of 12 surgically proven cases. In one case of cholangiocarcinoma, the site of obstruction was well shown on MR but a definite cause could not be ascertained. In another patient who developed intermittent jaundice following surgery for choledochal cyst, MR demonstrated a solitary stone in the common hepatic duct. Surgical confirmation could not be achieved as the patient was lost to follow up. There were 6 cases of choledocholithiasis, 3 cases of gall bladder carcinoma and one case each of pancreatic adenocarcinoma and cholangiocarcinoma. It is believed that MRI will provide obstructive jaundice and will be able to minimize the use of percutaneous transhepatic cholangiography (PTC) and endoscopic retrograde cholangiopancreatography (ERCP) in view of its ability to perform multiplanar imaging in multiple sequences.

Adenoma, Bile Duct↗
PubMed1989

Experimental selenium toxicity in guinea pigs: biochemical studies.

Biochemical studies were conducted in experimentally induced selenium toxicity in recently weaned guinea pigs. A significant drop in blood glucose level, in comparison to controls, was observed in animals fed selenium-enriched barley (organic form) as well as those fed ordinary barley mixed with sodium selenite (inorganic form). Estimation of total serum proteins also revealed a significant drop in both these groups. SGOT (EC 2.6.1.1) activity was comparatively lower but no significant alteration was noticed in SGPT (EC 2.6.1.2). The erythrocytic glutathione peroxidase activity was significantly increased in inorganic selenosis followed by that in organic one, in comparison to controls. All these alterations were of mild degree in guinea pigs which were given sodium arsenite (10 ppm) along with sodium selenite (30 ppm) in the feed.

Animals↗
PubMed1989

Experimental selenium toxicity in guinea pigs: haematological studies.

Haematological studies were conducted in recently weaned guinea pigs fed selenium-enriched barley (organic selenium) and barley mixed with sodium selenite (inorganic selenium). An attempt was made to study the effect of sodium arsenite supplementation in sodium selenite toxicity. A significant (p less than 0.01) decrease was noticed in the mean values of haemoglobin, haematocrit, mean corpuscular haemoglobin and mean corpuscular volume thereby indicating a microcytic hypochromic anaemia. The anaemia was comparatively more marked in guinea pigs fed selenium-enriched barley than in those kept on barley mixed with sodium selenite. There was a significant decrease in total leucocyte count which was the result of lymphocytopenia in organic toxicity and a decrease in both neutrophils and lymphocytes in inorganic toxicity. Dietary supplementation with sodium arsenite resulted in less reduction in the mean values of different erythrocytic indices thereby indicating that addition of sodium arsenite has some protective effect against toxicity with sodium selenite.

Anemia, Hypochromic↗
PubMed1989

Correlation between mouse intracerebral potency & 50 per cent histamine sensitizing dose of pertussis vaccine.

A good correlation was observed between mouse intracerebral potency in terms of International Units and 50 per cent histamine sensitizing dose (HSD50) of various types of pertussis vaccine. The correlation was significant irrespective of the inactivating agent used for the preparation of pertussis vaccine. If the potency of the vaccine increased, the HSD50 decreased and vice versa showing a negative correlation between potency and HSD50. The relative histamine sensitizing (HS) activities of various types of pertussis vaccines in comparison to that of heat inactivated pertussis vaccine (HIPV) obtained in different experiments were very similar although the HSD50 values of same types of vaccines obtained in these experiments varied greatly. The conventional HIPV preparations having potency around 8 IU per 40 x 10(9) organisms had HSD50 values in the range of 1.0 to 2.2 x 10(8) organisms. The estimation of HSD50 of pertussis vaccine has been found to be a useful measure of the toxicity of the vaccine and also correlates well with the potency of the vaccine.

Animals↗
PubMed1989

Laboratory evaluation of controlled-release repellent formulations on human volunteers under three climatic regimens.

Six controlled-release personal-use topical insect/arthropod repellent formulations of diethylmethylbenzamide (deet) were evaluated in an environmental chamber on volunteers for repellency against the mosquitoes Aedes aegypti and Ae. taeniorhynchus under three climatic regimens: basic variable high humidity (tropical environment), basic constant high humidity (forested and wet environment) and basic hot (hot-dry environment). The best protection under all the climatic regimens was provided by the Biotek formulation. In a tropical environment, some formulations induced more biting from mosquitoes than the concurrent untreated control in the late hours of the testing. Repellency was not directly related to the deet concentration in the various controlled-release repellent formulations.

Aedes↗